You are setting yourself up for one of those 3000 post threads. This is a tremendously simple yet complicated question. Yes dopamine does get replaced by dopa, But why isn't L-dopa the best feel-good drug there is, and why don't things like cocaine, which are so called dopamine releaser's cause euphoria in the PWP. This question needs the input of a seasoned neurologist, and it only brings more questions to the table